WordPress Keyboard Shortcuts for Visual Post Editor

Ctrl + b = Bold
Ctrl + i = Italic
Ctrl + c = Copy
Ctrl + v = Paste
Ctrl + x = Cut
Ctrl + a = Select All
Ctrl + z = Undo
Ctrl + y = Redo
Ctrl + [number] = Insert heading sizes, e.g. CTRL+1 = <h1>, CTRL+2 = <h2>.
Alt + Shift + n = Check Spelling
Alt + Shift + l = Align Left
Alt + Shift + j = Justify Text
Alt + Shift + c = Align Center
Alt + Shift + d = Strikethrough
Alt + Shift + r = Align Right
Alt + Shift + u = Unordered List
Alt + Shift + a = Insert link
Alt + Shift + o = Numeric List
Alt + Shift + s = Remove link
Alt + Shift + q = Quote
Alt + Shift + m = Insert Image
Alt + Shift + w = Full screen distraction free writing mode
Alt + Shift + t = Insert More Tag
Alt + Shift + p = Insert Page Break tag
Alt + Shift + h = Rich text editor help

WordPress Keyboard Shortcuts for Plain Text Editor

Ctrl + c = Copy
Ctrl + v = Paste
Ctrl + x = Cut
Ctrl + z = Undo
Ctrl + y = Redo
Ctrl + p = Print
Alt + Shift + p = Publish
Alt + Shift + f = Fullscreen distraction free writing

WordPress Keyboard Shortcuts for Comments Screen

J = Next comment (moves the current selection down)
K = Previous comment (moves the current selection up)
A = Approve comment
U = Unapprove comment
D = Delete comment
R = Reply comment
Q = Quick edit a comment
Z = Restore Comment from Trash or Undo if you Delete a comment

Shift + A = Approve checked comments
Shift + D = Delete checked comments
Shift + U = Unapprove selected comments
Shift + T = Move selected comments to trash
Shift + Z = Restore selected comments from trash